DESCRIPTION: The Candidate in this revised application for a K23 Award has graduate clinical training in Pediatric Dentistry and PhD level research training in Microbiology and in Cariology. The purpose of the requested Award is to provide the candidate with multidisciplinary training in patient-oriented research, which will help her design and conduct translational studies related to biological predictors of caries risk in children. The Career Development Plan of this proposal consists of a multidisciplinary program, which includes training in the responsible conduct of research, epidemiology, biostatistics and clinical research design, among others. The plan also includes a number of activities that will provide additional hands-on experience in clinical research and continuous training in molecular biology throughout the Award period. The Research component of this application consists of a combined clinical and basic research study, which aims to address the role bacterial urease activity in the development of dental caries in children. Bacterial urease activity in dental plaque generates ammonia, which is believed to inhibit the development of dental caries, and which can also influence the oral microbial ecology. If these relationships can be demonstrated, future studies could lead to the development of novel methods for caries risk assessment and prevention. The primary mentor is Dr. Augusto Elias, Professor and Director of the Research Office in the UPR School of Dentistry. Dr. Elias has extensive experience as a mentor, as a reference examiner in caries studies worldwide, and as the principal investigator of numerous corporate-sponsored dental clinical trials and prevalence studies in Puerto Rico. Dr. Elias will be joined in his role as a mentor by two co-mentors, Dr. Ronald Billings (University of Rochester) and Dr. Robert Burne (University of Florida) who will provide expert advice and technical support to the clinical and the basic science portion of the study, respectively. Dr. Erick Suarez, Professor in Biostatistics, will guide the candidate in study design methodology and in the analysis of the data.